Very interesting stuff. Thanks for the detailed explanation, Levi. And for the link, Codifies. BitScope looks like a great option, I will be sure to give it a try. I definitely don't know anything about the specifics of how what is possible but I have previously looked into specialised hardware for this sort of signal processing. It is definitely possible to do amazing things with nominal system specs, but it is quite possible that discrete logic chips are used for the tricky processing. If this is the case, and assuming the Pyra does not include this logic, I would agree with FlapJack that this is something to be added in future designs.
For serious applications, I would certainly use a specialised solution, such as the BitScope products or HackRF. I imagine these would handle most of the system resource load as well and function properly with a Pyra or Pandora, please correct me if I am wrong. Obviously another consideration is the antenna or electrical probe/clip, but that would be necessary regardless of the interface. If this sort of specialised tech could be built into the Pyra, I would happily pay an extra 50% for it. Like the mobile data, this could be an optional controller to replace the standard audio controller. Alternatively, new U.S.B. specs like 3.1 and Type-C seem to support high output currents. I'm not sure how precisely the controllers can be configured but I know that there are provisions for negotiating additional power over multiple wires. 100W at 12V-24V would be perfectly useful as a variable power supply, or perhaps as a variable resistor through loop-back. I think the specs might cut off at 20V but this is something somebody else would need to look into in the future. Obviously these won't be on the current Pyra version but it may be a better method than replacing the audio controller, at least for electronics applications.
As for what a normal sound controller might be possible of, I believe using a normal sound controller would limit the theoretical frequency range to at least 20Hz-20kHz, in line with the audible range. As I said before, less precision may be required if a program is interpreting the data rather than a human. This range has some uses for radio applications but probably not many for electronics. I believe the usable sample rate of a 192kHz sound controller would translate to an oscilloscope sample rate of 48-96kHz (Link-1 below). Audio line level for consumer audio products is supposed to be 0.447 Vpk nominal and 1.736 Vpk nominal for professional audio products (Link-2). Max voltage, corresponding to decibel level, seems to be a tricky point for consumer sound controllers due to an industry arms-race for volume. 5V seems to be a reasonable expectation for voltage output but some sources report 24V or 60V for reasons I do not understand (Link-3). Input rating for an audio controller seems to be much lower than output since it would be "mic level" rather than "line level". I found one source that suggests 447 mVpk, but I could not corroborate this (Link-4).
There are apparently many resources describing the adaptation of a P.C. for use as an oscilloscope but I cannot be sure how safe or accurate the information is. One resource I found suggests that input can be attenuated significantly but the laptop may be at risk despite resistive circuitry (Link-5; see "NOTES:" at bottom of article).
Again, I really don't know much about this technology or the basic sciences. This sort of education is one of the reasons I am so interested in having these versatile resources available. My ideas can be taken with a grain of salt, but they do seem useful to me. Maybe others will find them useful as well.
Link-1:
http://www.ni.com/white-paper/4333/en/#toc2
Link-2:
http://electronics.stackexchange.co...nge-of-a-standard-headphone-jack-from-a-phone
Link-3:
http://electronics.stackexchange.co...-typical-max-voltage-out-of-a-pc-speaker-jack
Link-4:
http://electronics.stackexchange.co...he-typical-max-voltage-for-sound-card-line-in
Link-5:
http://www.instructables.com/id/Use-Your-Laptop-as-Oscilloscope/?ALLSTEPS
